<?php

/*
	Question2Answer (c) Gideon Greenspan

	http://www.question2answer.org/

	
	File: qa-include/qa-db-cookies.php
	Version: See define()s at top of qa-include/qa-base.php
	Description: Database access functions for user cookies


	This program is free software; you can redistribute it and/or
	modify it under the terms of the GNU General Public License
	as published by the Free Software Foundation; either version 2
	of the License, or (at your option) any later version.
	
	This program is distributed in the hope that it will be useful,
	but WITHOUT ANY WARRANTY; without even the implied warranty of
	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
	GNU General Public License for more details.

	More about this license: http://www.question2answer.org/license.php
*/

if (!defined('QA_VERSION')) { // don't allow this page to be requested directly from browser
    header('Location: ../');
    exit;
}


function qa_db_cookie_create($ipaddress)
    /*
        Create a new random cookie for $ipaddress and insert into database, returning it
    */
{
    for ($attempt = 0; $attempt < 10; $attempt++) {
        $cookieid = qa_db_random_bigint();

        if (qa_db_cookie_exists($cookieid))
            continue;

        qa_db_query_sub(
            'INSERT INTO ^cookies (cookieid, created, createip) ' .
                'VALUES (#, NOW(), COALESCE(INET_ATON($), 0))',
            $cookieid, $ipaddress
        );

        return $cookieid;
    }

    return null;
}


function qa_db_cookie_written($cookieid, $ipaddress)
    /*
        Note in database that a write operation has been done by user identified by $cookieid and from $ipaddress
    */
{
    qa_db_query_sub(
        'UPDATE ^cookies SET written=NOW(), writeip=COALESCE(INET_ATON($), 0) WHERE cookieid=#',
        $ipaddress, $cookieid
    );
}


function qa_db_cookie_exists($cookieid)
    /*
        Return whether $cookieid exists in database
    */
{
    return qa_db_read_one_value(qa_db_query_sub(
        'SELECT COUNT(*) FROM ^cookies WHERE cookieid=#',
        $cookieid
    )) > 0;
}


/*
	Omit PHP closing tag to help avoid accidental output
*/